Upstream builds a single static binary (main.go at repo root, no
cmd/... subpackage) that go:embeds templates/ and assets/ at compile
time, and uses a relative ./db directory (jsondb) instead of SQLite -
so WorkingDirectory in the systemd unit now matters for the DB path,
not for template/static serving like before.
Frontend assets (admin-lte, jquery plugins) need yarn + prepare_assets.sh
before go build, so all installers now also install nodejs/npm/yarn and
run prepare_assets.sh when assets/dist is missing or package.json changed.
Binary is now literally named "wireguard-ui" (matches upstream), listens
on 0.0.0.0:5000 by default. systemd unit rewritten accordingly with
WorkingDirectory=/var/lib/wireguard-ui-multi.
Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>
